// ========================================================================
// Copyright (c) 2004-2009 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
// The Eclipse Public License is available at
// http://www.eclipse.org/legal/epl-v10.html
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
// You may elect to redistribute this code under either of these licenses.
// ========================================================================

package org.eclipse.jetty.util;

import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.net.URL;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;

import org.eclipse.jetty.util.log.Log;
import org.eclipse.jetty.util.log.Logger;

/* ------------------------------------------------------------ */
/**
 * TYPE Utilities. Provides various static utiltiy methods for manipulating types and their string representations.
 * 
 * @since Jetty 4.1
 */
@SuppressWarnings({ "rawtypes", "unchecked" })
public class TypeUtil
{

	private static final Logger LOG = Log.getLogger(TypeUtil.class);
	public static int CR = '\015';
	public static int LF = '\012';

	/* ------------------------------------------------------------ */

	private static final HashMap<String, Class> name2Class = new HashMap<String, Class>();
	static
	{
		name2Class.put("boolean", java.lang.Boolean.TYPE);
		name2Class.put("byte", java.lang.Byte.TYPE);
		name2Class.put("char", java.lang.Character.TYPE);
		name2Class.put("double", java.lang.Double.TYPE);
		name2Class.put("float", java.lang.Float.TYPE);
		name2Class.put("int", java.lang.Integer.TYPE);
		name2Class.put("long", java.lang.Long.TYPE);
		name2Class.put("short", java.lang.Short.TYPE);
		name2Class.put("void", java.lang.Void.TYPE);

		name2Class.put("java.lang.Boolean.TYPE", java.lang.Boolean.TYPE);
		name2Class.put("java.lang.Byte.TYPE", java.lang.Byte.TYPE);
		name2Class.put("java.lang.Character.TYPE", java.lang.Character.TYPE);
		name2Class.put("java.lang.Double.TYPE", java.lang.Double.TYPE);
		name2Class.put("java.lang.Float.TYPE", java.lang.Float.TYPE);
		name2Class.put("java.lang.Integer.TYPE", java.lang.Integer.TYPE);
		name2Class.put("java.lang.Long.TYPE", java.lang.Long.TYPE);
		name2Class.put("java.lang.Short.TYPE", java.lang.Short.TYPE);
		name2Class.put("java.lang.Void.TYPE", java.lang.Void.TYPE);

		name2Class.put("java.lang.Boolean", java.lang.Boolean.class);
		name2Class.put("java.lang.Byte", java.lang.Byte.class);
		name2Class.put("java.lang.Character", java.lang.Character.class);
		name2Class.put("java.lang.Double", java.lang.Double.class);
		name2Class.put("java.lang.Float", java.lang.Float.class);
		name2Class.put("java.lang.Integer", java.lang.Integer.class);
		name2Class.put("java.lang.Long", java.lang.Long.class);
		name2Class.put("java.lang.Short", java.lang.Short.class);

		name2Class.put("Boolean", java.lang.Boolean.class);
		name2Class.put("Byte", java.lang.Byte.class);
		name2Class.put("Character", java.lang.Character.class);
		name2Class.put("Double", java.lang.Double.class);
		name2Class.put("Float", java.lang.Float.class);
		name2Class.put("Integer", java.lang.Integer.class);
		name2Class.put("Long", java.lang.Long.class);
		name2Class.put("Short", java.lang.Short.class);

		name2Class.put(null, java.lang.Void.TYPE);
		name2Class.put("string", java.lang.String.class);
		name2Class.put("String", java.lang.String.class);
		name2Class.put("java.lang.String", java.lang.String.class);
	}

	/* ------------------------------------------------------------ */
	private static final HashMap<Class, String> class2Name = new HashMap<Class, String>();
	static
	{
		class2Name.put(java.lang.Boolean.TYPE, "boolean");
		class2Name.put(java.lang.Byte.TYPE, "byte");
		class2Name.put(java.lang.Character.TYPE, "char");
		class2Name.put(java.lang.Double.TYPE, "double");
		class2Name.put(java.lang.Float.TYPE, "float");
		class2Name.put(java.lang.Integer.TYPE, "int");
		class2Name.put(java.lang.Long.TYPE, "long");
		class2Name.put(java.lang.Short.TYPE, "short");
		class2Name.put(java.lang.Void.TYPE, "void");

		class2Name.put(java.lang.Boolean.class, "java.lang.Boolean");
		class2Name.put(java.lang.Byte.class, "java.lang.Byte");
		class2Name.put(java.lang.Character.class, "java.lang.Character");
		class2Name.put(java.lang.Double.class, "java.lang.Double");
		class2Name.put(java.lang.Float.class, "java.lang.Float");
		class2Name.put(java.lang.Integer.class, "java.lang.Integer");
		class2Name.put(java.lang.Long.class, "java.lang.Long");
		class2Name.put(java.lang.Short.class, "java.lang.Short");

		class2Name.put(null, "void");
		class2Name.put(java.lang.String.class, "java.lang.String");
	}

	/* ------------------------------------------------------------ */
	private static final HashMap<Class, Method> class2Value = new HashMap<Class, Method>();
	static
	{
		try
		{
			Class[] s = { java.lang.String.class };

			class2Value.put(java.lang.Boolean.TYPE,
				java.lang.Boolean.class.getMethod("valueOf", s));
			class2Value.put(java.lang.Byte.TYPE,
				java.lang.Byte.class.getMethod("valueOf", s));
			class2Value.put(java.lang.Double.TYPE,
				java.lang.Double.class.getMethod("valueOf", s));
			class2Value.put(java.lang.Float.TYPE,
				java.lang.Float.class.getMethod("valueOf", s));
			class2Value.put(java.lang.Integer.TYPE,
				java.lang.Integer.class.getMethod("valueOf", s));
			class2Value.put(java.lang.Long.TYPE,
				java.lang.Long.class.getMethod("valueOf", s));
			class2Value.put(java.lang.Short.TYPE,
				java.lang.Short.class.getMethod("valueOf", s));

			class2Value.put(java.lang.Boolean.class,
				java.lang.Boolean.class.getMethod("valueOf", s));
			class2Value.put(java.lang.Byte.class,
				java.lang.Byte.class.getMethod("valueOf", s));
			class2Value.put(java.lang.Double.class,
				java.lang.Double.class.getMethod("valueOf", s));
			class2Value.put(java.lang.Float.class,
				java.lang.Float.class.getMethod("valueOf", s));
			class2Value.put(java.lang.Integer.class,
				java.lang.Integer.class.getMethod("valueOf", s));
			class2Value.put(java.lang.Long.class,
				java.lang.Long.class.getMethod("valueOf", s));
			class2Value.put(java.lang.Short.class,
				java.lang.Short.class.getMethod("valueOf", s));
		} catch (Exception e)
		{
			e.printStackTrace();
		}
	}

	/* ------------------------------------------------------------ */
	/**
	 * Array to List.
	 * <p>
	 * Works like {@link Arrays#asList(Object...)}, but handles null arrays.
	 * 
	 * @return a list backed by the array.
	 */
	public static <T> List<T> asList(T[] a)
	{
		if (a == null)
			return Collections.emptyList();
		return Arrays.asList(a);
	}

	/* ------------------------------------------------------------ */
	/**
	 * Class from a canonical name for a type.
	 * 
	 * @param name A class or type name.
	 * @return A class , which may be a primitive TYPE field..
	 */
	public static Class fromName(String name)
	{
		return name2Class.get(name);
	}

	/* ------------------------------------------------------------ */
	/**
	 * Canonical name for a type.
	 * 
	 * @param type A class , which may be a primitive TYPE field.
	 * @return Canonical name.
	 */
	public static String toName(Class type)
	{
		return class2Name.get(type);
	}

	/* ------------------------------------------------------------ */
	/**
	 * Convert String value to instance.
	 * 
	 * @param type The class of the instance, which may be a primitive TYPE field.
	 * @param value The value as a string.
	 * @return The value as an Object.
	 */
	public static Object valueOf(Class type, String value)
	{
		try
		{
			if (type.equals(java.lang.String.class))
				return value;

			Method m = class2Value.get(type);
			if (m != null)
				return m.invoke(null, value);

			if (type.equals(java.lang.Character.TYPE) ||
				type.equals(java.lang.Character.class))
				return new Character(value.charAt(0));

			Constructor c = type.getConstructor(java.lang.String.class);
			return c.newInstance(value);
		} catch (NoSuchMethodException e)
		{
			// LogSupport.ignore(log,e);
		} catch (IllegalAccessException e)
		{
			// LogSupport.ignore(log,e);
		} catch (InstantiationException e)
		{
			// LogSupport.ignore(log,e);
		} catch (InvocationTargetException e)
		{
			if (e.getTargetException() instanceof Error)
				throw (Error)(e.getTargetException());
			// LogSupport.ignore(log,e);
		}
		return null;
	}

	/* ------------------------------------------------------------ */
	/**
	 * Convert String value to instance.
	 * 
	 * @param type classname or type (eg int)
	 * @param value The value as a string.
	 * @return The value as an Object.
	 */
	public static Object valueOf(String type, String value)
	{
		return valueOf(fromName(type), value);
	}

	/* ------------------------------------------------------------ */
	/**
	 * Parse an int from a substring. Negative numbers are not handled.
	 * 
	 * @param s String
	 * @param offset Offset within string
	 * @param length Length of integer or -1 for remainder of string
	 * @param base base of the integer
	 * @return the parsed integer
	 * @throws NumberFormatException if the string cannot be parsed
	 */
	public static int parseInt(String s, int offset, int length, int base)
		throws NumberFormatException
	{
		int value = 0;

		if (length < 0)
			length = s.length() - offset;

		for (int i = 0; i < length; i++)
		{
			char c = s.charAt(offset + i);

			int digit = c - '0';
			if (digit < 0 || digit >= base || digit >= 10)
			{
				digit = 10 + c - 'A';
				if (digit < 10 || digit >= base)
					digit = 10 + c - 'a';
			}
			if (digit < 0 || digit >= base)
				throw new NumberFormatException(s.substring(offset, offset + length));
			value = value * base + digit;
		}
		return value;
	}

	/* ------------------------------------------------------------ */
	/**
	 * Parse an int from a byte array of ascii characters. Negative numbers are not handled.
	 * 
	 * @param b byte array
	 * @param offset Offset within string
	 * @param length Length of integer or -1 for remainder of string
	 * @param base base of the integer
	 * @return the parsed integer
	 * @throws NumberFormatException if the array cannot be parsed into an integer
	 */
	public static int parseInt(byte[] b, int offset, int length, int base)
		throws NumberFormatException
	{
		int value = 0;

		if (length < 0)
			length = b.length - offset;

		for (int i = 0; i < length; i++)
		{
			char c = (char)(0xff & b[offset + i]);

			int digit = c - '0';
			if (digit < 0 || digit >= base || digit >= 10)
			{
				digit = 10 + c - 'A';
				if (digit < 10 || digit >= base)
					digit = 10 + c - 'a';
			}
			if (digit < 0 || digit >= base)
				throw new NumberFormatException(new String(b, offset, length));
			value = value * base + digit;
		}
		return value;
	}

	/* ------------------------------------------------------------ */
	public static byte[] parseBytes(String s, int base)
	{
		byte[] bytes = new byte[s.length() / 2];
		for (int i = 0; i < s.length(); i += 2)
			bytes[i / 2] = (byte)TypeUtil.parseInt(s, i, 2, base);
		return bytes;
	}

	/* ------------------------------------------------------------ */
	public static String toString(byte[] bytes, int base)
	{
		StringBuilder buf = new StringBuilder();
		for (byte b: bytes)
		{
			int bi = 0xff & b;
			int c = '0' + (bi / base) % base;
			if (c > '9')
				c = 'a' + (c - '0' - 10);
			buf.append((char)c);
			c = '0' + bi % base;
			if (c > '9')
				c = 'a' + (c - '0' - 10);
			buf.append((char)c);
		}
		return buf.toString();
	}

	/* ------------------------------------------------------------ */
	/**
	 * @param b An ASCII encoded character 0-9 a-f A-F
	 * @return The byte value of the character 0-16.
	 */
	public static byte convertHexDigit(byte b)
	{
		if ((b >= '0') && (b <= '9'))
			return (byte)(b - '0');
		if ((b >= 'a') && (b <= 'f'))
			return (byte)(b - 'a' + 10);
		if ((b >= 'A') && (b <= 'F'))
			return (byte)(b - 'A' + 10);
		throw new IllegalArgumentException("!hex:" + Integer.toHexString(0xff & b));
	}

	/* ------------------------------------------------------------ */
	public static void toHex(byte b, Appendable buf)
	{
		try
		{
			int bi = 0xff & b;
			int c = '0' + (bi / 16) % 16;
			if (c > '9')
				c = 'A' + (c - '0' - 10);
			buf.append((char)c);
			c = '0' + bi % 16;
			if (c > '9')
				c = 'A' + (c - '0' - 10);
			buf.append((char)c);
		} catch (IOException e)
		{
			throw new RuntimeException(e);
		}
	}

	/* ------------------------------------------------------------ */
	public static String toHexString(byte b)
	{
		return toHexString(new byte[] { b }, 0, 1);
	}

	/* ------------------------------------------------------------ */
	public static String toHexString(byte[] b)
	{
		return toHexString(b, 0, b.length);
	}

	/* ------------------------------------------------------------ */
	public static String toHexString(byte[] b, int offset, int length)
	{
		StringBuilder buf = new StringBuilder();
		for (int i = offset; i < offset + length; i++)
		{
			int bi = 0xff & b[i];
			int c = '0' + (bi / 16) % 16;
			if (c > '9')
				c = 'A' + (c - '0' - 10);
			buf.append((char)c);
			c = '0' + bi % 16;
			if (c > '9')
				c = 'a' + (c - '0' - 10);
			buf.append((char)c);
		}
		return buf.toString();
	}

	/* ------------------------------------------------------------ */
	public static byte[] fromHexString(String s)
	{
		if (s.length() % 2 != 0)
			throw new IllegalArgumentException(s);
		byte[] array = new byte[s.length() / 2];
		for (int i = 0; i < array.length; i++)
		{
			int b = Integer.parseInt(s.substring(i * 2, i * 2 + 2), 16);
			array[i] = (byte)(0xff & b);
		}
		return array;
	}

	public static void dump(Class c)
	{
		System.err.println("Dump: " + c);
		dump(c.getClassLoader());
	}

	public static void dump(ClassLoader cl)
	{
		System.err.println("Dump Loaders:");
		while (cl != null)
		{
			System.err.println("  loader " + cl);
			cl = cl.getParent();
		}
	}

	/* ------------------------------------------------------------ */
	public static byte[] readLine(InputStream in) throws IOException
	{
		byte[] buf = new byte[256];

		int i = 0;
		int loops = 0;
		int ch = 0;

		while (true)
		{
			ch = in.read();
			if (ch < 0)
				break;
			loops++;

			// skip a leading LF's
			if (loops == 1 && ch == LF)
				continue;

			if (ch == CR || ch == LF)
				break;

			if (i >= buf.length)
			{
				byte[] old_buf = buf;
				buf = new byte[old_buf.length + 256];
				System.arraycopy(old_buf, 0, buf, 0, old_buf.length);
			}
			buf[i++] = (byte)ch;
		}

		if (ch == -1 && i == 0)
			return null;

		// skip a trailing LF if it exists
		if (ch == CR && in.available() >= 1 && in.markSupported())
		{
			in.mark(1);
			ch = in.read();
			if (ch != LF)
				in.reset();
		}

		byte[] old_buf = buf;
		buf = new byte[i];
		System.arraycopy(old_buf, 0, buf, 0, i);

		return buf;
	}

	public static URL jarFor(String className)
	{
		try
		{
			className = className.replace('.', '/') + ".class";
			// hack to discover jstl libraries
			URL url = Loader.getResource(null, className, false);
			String s = url.toString();
			if (s.startsWith("jar:file:"))
				return new URL(s.substring(4, s.indexOf("!/")));
		} catch (Exception e)
		{
			LOG.ignore(e);
		}
		return null;
	}

	public static Object call(Class<?> oClass, String method, Object obj, Object[] arg)
		throws InvocationTargetException, NoSuchMethodException
	{
		// Lets just try all methods for now
		Method[] methods = oClass.getMethods();
		for (int c = 0; methods != null && c < methods.length; c++)
		{
			if (!methods[c].getName().equals(method))
				continue;
			if (methods[c].getParameterTypes().length != arg.length)
				continue;
			if (Modifier.isStatic(methods[c].getModifiers()) != (obj == null))
				continue;
			if ((obj == null) && methods[c].getDeclaringClass() != oClass)
				continue;

			try
			{
				return methods[c].invoke(obj, arg);
			} catch (IllegalAccessException e)
			{
				LOG.ignore(e);
			} catch (IllegalArgumentException e)
			{
				LOG.ignore(e);
			}
		}

		throw new NoSuchMethodException(method);
	}
}
